Brainy Motors Promise Big Leap in Energy Efficiency

Electric motors are everywhere. They lift elevators, bring conditioned air to your desk, make your washing machine agitate and your PC hard drive spin. What’s surprising is that they are quietly – or not so quietly – consuming more electricity than any other single use. One company is working to change that.


HEVT motor

The guts of HEVT’s high performance SRM motors: the stator and rotor. (HEVT graphic)

Motors’ outsize appetite for energy means they represent a lucrative opportunity for saving energy and money in almost every business sector. A new company called HEVT hopes to capitalize on that opportunity.

My Earth Day column today talks about the need to tackle energy waste by improving the efficiency of motors. I calculated (using figures from the International Energy Agency) that businesses worldwide now spend $475 billion per year to power motors, and saving just one percent of that energy would cut energy bills by billions of dollars annually.

Over the years there have been many advances that have made motors more energy-efficient. These power-hungry devices have undergone performance improvements such as the use of permanent magnets. Variable speed drive systems allow motors to run at their most efficient speeds. Control systems turn motors off when they’re not needed, and help businesses participate in demand response programs offered by their energy utilities. Together, all of these have the potential for double-digit reductions in how much electricity motors consume.

 

THERE’S ALWAYS ROOM for improvement, especially in motors themselves. The R&D challenge is to make more efficient motors without driving up the unit cost and hampering their adoption.

The motors that consume the most electricity today are midsize motors — like those used in fans, compressors and pumps — because there are so many of them. Compact, powerful magnets called rare earth magnets help to make these more efficient. But in the long term, rare earth magnets have their drawbacks.

Only about 13 percent of the world’s reserves of rare earth metals are in the United States. China has the largest share of reserves, and a near monopoly on refining — accounting for more than 95 percent of worldwide production. Rare earth processing in China is a messy process that uses toxic chemicals, and workers have little protection, writes American Foreign Policy Council senior fellow Eric Hannis in US News. And resource control by one country has led to supply constraints and cost volatility for motor manufacturers.

 

HEVT IS DEVELOPING high-performance motors based on switched reluctance machine technology, or SRM. What’s different about SRM is that it sends pulses of electric current to the stationary part of the motor, not to the rotating part. What conventional motor designs accomplished with copper windings and active materials, SRM motors accomplish with software and power electronics.

Why didn’t engineers think of this sooner? They did – a century ago – but until recently they didn’t have the switching technology needed to make SRM motors run as smoothly as their conventional counterparts. Another advantage of SRM motors is that they don’t rely on rare earth magnets.

“We have high-performance, highly efficient electric motor technologies that are free of rare earth metals, and more reliable,” says HEVT CEO and co-founder Heidi Lubin. “We reduce the initial costs as much as 60 percent, while providing up to three times more efficiency relative to competitive technologies.”

It’s not just the mechanical design that makes HEVT’s motors more efficient. Software and power electronics are a key component – they provide the “smarts” that make rare earth magnets unnecessary. As Lubin puts it, HEVT has improved the muscle and the brain of electric motors. Software also provides a platform for improving motors even after they’re installed.

“Software will provide opportunities into the future for enabling add-on functionality, like demand response, net metering , and reliability monitoring,” Lubin says.

The first place we might see HEVT motors is in electric bicycles; then in heating, ventilating and air conditioning systems. HVAC represents a big portion of building energy cost, in part because of the number of motors running fans and compressors.

For now, though, you can’t buy an SRM motor from HEVT. The company is working on joint development, manufacturing, and licensing arrangements, but hasn’t hinted at a timeframe for commercially available products.

 

THE SCIENCE BEHIND HEVT’s motors was the subject of research by company founder Dr. Ali Emadi at the Illinois Institute of Technology’s Power Electronics and Motor Drives Laboratory.

Lubin explains,  “I became involved as a result of my graduate research on renewable energy and electrified transportation. Since the late 1990s I’ve had a long-term interest in and vision around distributed energy and mobility.”

Angel funding and government grants got HEVT to the prototype stage. The company entered the Cleantech Open in 2012 and walked away with the national grand prize of $250,000 cash and in-kind services.

Founder Heidi Lubin offers one piece of advice to other cleantech entrepreneurs from her experience: “Take the time to understand your value, both as an entrepreneur to your organization and also the organization’s value in the market.  It’s important to understand your unique value proposition. It can be a challenging question to answer, but an important one.”

 

About the Author:
http://energypriorities.com

Denis founded Energy Priorities Magazine on Earth Day 2004 and hosts the radio program by the same name distributed by NPR. He has authored hundreds of cleantech articles for a variety of publications, ranging from Sustainable Industries Journal to the New York Times, and he has been interviewed by major news outlets, including FORTUNE and MSNBC. He lives in the Seattle, WA area. Follow him on Twitter: @Cleantech. Contact him here. Disclosure information.

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